On Fri, Apr 2, 2021 at 12:36 AM Christophe Leroy
<christophe.le...@csgroup.eu> wrote:
>
>
>
> Le 30/03/2021 à 06:51, Jordan Niethe a écrit :
> > If MODULES_{VADDR,END} are not defined set them to VMALLOC_START and
> > VMALLOC_END respectively. This reduces the need for special cases. For
> > example, powerpc's module_alloc() was previously predicated on
> > MODULES_VADDR being defined but now is unconditionally defined.
> >
> > This will be useful reducing conditional code in other places that need
> > to allocate from the module region (i.e., kprobes).
> >
> > Signed-off-by: Jordan Niethe <jniet...@gmail.com>
> > ---
> > v10: New to series
> > ---
> > arch/powerpc/include/asm/pgtable.h | 5 +++++
> > arch/powerpc/kernel/module.c | 5 +----
>
> You probably also have changes to do in kernel/ptdump.c
>
> In mm/book3s32/mmu.c and mm/kasan/kasan_init_32.c as well allthough that's
> harmless here.
>
> > 2 files changed, 6 insertions(+), 4 deletions(-)
> >
> > diff --git a/arch/powerpc/include/asm/pgtable.h
> > b/arch/powerpc/include/asm/pgtable.h
> > index 4eed82172e33..014c2921f26a 100644
> > --- a/arch/powerpc/include/asm/pgtable.h
> > +++ b/arch/powerpc/include/asm/pgtable.h
> > @@ -167,6 +167,11 @@ struct seq_file;
> > void arch_report_meminfo(struct seq_file *m);
> > #endif /* CONFIG_PPC64 */
> >
> > +#ifndef MODULES_VADDR
> > +#define MODULES_VADDR VMALLOC_START
> > +#define MODULES_END VMALLOC_END
> > +#endif
> > +
> > #endif /* __ASSEMBLY__ */
> >
> > #endif /* _ASM_POWERPC_PGTABLE_H */
> > diff --git a/arch/powerpc/kernel/module.c b/arch/powerpc/kernel/module.c
> > index a211b0253cdb..f1fb58389d58 100644
> > --- a/arch/powerpc/kernel/module.c
> > +++ b/arch/powerpc/kernel/module.c
> > @@ -14,6 +14,7 @@
> > #include <asm/firmware.h>
> > #include <linux/sort.h>
> > #include <asm/setup.h>
> > +#include <linux/mm.h>
> >
> > static LIST_HEAD(module_bug_list);
> >
> > @@ -87,13 +88,9 @@ int module_finalize(const Elf_Ehdr *hdr,
> > return 0;
> > }
> >
> > -#ifdef MODULES_VADDR
> > void *module_alloc(unsigned long size)
> > {
> > - BUILD_BUG_ON(TASK_SIZE > MODULES_VADDR);
> > -
>
> The above check is needed somewhere, if you remove it from here you have to
> perform the check
> somewhere else.
This also introduces this warning:
fs/proc/kcore.c:626:52: warning: self-comparison always evaluates to
false [-Wtautological-compare]
626 | if (MODULES_VADDR != VMALLOC_START && MODULES_END != VMALLOC_END) {
I might leave this patch out of this series and use an #ifdef for now
and make this change separately as a follow up.
>
> > return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
> > GFP_KERNEL,
> > PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS,
> > NUMA_NO_NODE,
> > __builtin_return_address(0));
> > }
> > -#endif
> >
